Gas Sensors Based on Mechanically Exfoliated MoS(2) Nanosheets for Room-Temperature NO(2) Detection

The unique properties of MoS(2) nanosheets make them a promising candidate for high-performance room temperature gas detection. Herein, few-layer MoS(2) nanosheets (FLMN) prepared via mechanical exfoliation are coated on a substrate with interdigital electrodes for room-temperature NO(2) detection. Interestingly, compared with other NO(2) gas sensors based on MoS(2), FLMN gas sensors exhibit high responsivity for room-temperature NO(2) detection, and NO(2) is easily desorbed from the sensor surface with an ultrafast recovery behavior, with recovery times around 2 s. The high responsivity is related to the fact that the adsorbed NO(2) can affect the electron states within the entire material, which is attributed to the very small thickness of the MoS(2) nanosheets. First-principles calculations were carried out based on the density functional theory (DFT) to verify that the ultrafast recovery behavior arises from the weak van der Waals binding between NO(2) and the MoS(2) surface. Our work suggests that FLMN prepared via mechanical exfoliation have a great potential for fabricating high-performance NO(2) gas sensors.